Hi Mike
I would have said so last week BUT have been up to Caburn this evening. I was expecting to see more than the two dozen I saw out on Frisay after a few days sun in Sussex. But it took ten minutes hunting to find my first, even though it's a familiar local site, and I sould say if I saw twenty I was lucky - many of these recognisably the same I saw Friday and starting to go over. I only saw two or three opening rather than fully out. So though I'd love to be proved wrong I'd say this is a very poor year, easily the worst in the five years I've known the site, which usually has a hundred in a bad year and a thousand in a good year. The burnt orchids grow on what becomes quite tall grass and I'd suspect that the stop-start weather has favoured taller vegetation and is making it tough for the burnt orchids this year.
It depends how you like your orchid expeditions. I'd say from visits that after this weekend the Early Spiders at Castle Hill and the few Burnt at Caburn will both be going over. If visiting, at Caburn the very few Burnt is quite a challenge even with knowledge of the site or good directions and I'd say could number less than ten good specimens if my interpretation is right; Castle Hill will have lots more Early Spiders (Early Purple also but will be going over) and much more chance of seeing a good number of fine orchids in good condition.
Both are lovely walks - Glynde to Lewes is a classic short downland walk.